In a prospective, blinded placebo-controlled randomized trial, treatment naïve HIV-infected subjects initiating HAART will be assigned to HAART + zoledronic acid or HAART + placebo. Serial assessment of serum levels of bone markers, cellular expression of OPG/RANKL and other cytokines, cellular immune activation markers, serum bone regulating hormones, and bone mineral density (BMD) by DXA scan will be undertaken at pre-defined time points from baseline through week 144 of HAART.